1. Field
The present invention relates generally to the utilization of commonly replaced system parts. The invention relates in particular to Customer Replaceable Units (CRU) and Customer Replaceable Unit Monitors (CRUM) used for their identification.
2. Description of Related Art
Many machines have replaceable sub-assemblies. Printing machines, for example, may have a number of replaceable sub-assemblies, such as a fuser print cartridge, a toner cartridge, or an automatic document handler. These subassemblies may be arranged as a unit called a cartridge, and if intended for replacement by the customer or machine owner, may be referred to as a Customer Replaceable Unit or CRU. Examples of CRUs may include a printer cartridge, a toner cartridge, or a transfer assembly unit. It may be desirable for a CRU design to vary over the course of time due to manufacturing changes or to solve post-launch problems with either the machine, the CRU, or an interaction between the CRU and the machine. Further, design optimizations may be recognized subsequent to design launch and machine sale, for example, that a relatively simple code update might realize. However, solving these problems, or providing optimization updates, generally requires a service call.
U.S. Pat. No. 4,961,088 to Gilliland et al. discloses a monitor/warranty system for electrostatographic reproducing machines in which replaceable cartridges providing a predetermined number of images are used. Each cartridge has an EEPROM programmed with a cartridge identification number that, when matched with a cartridge identification number in the machine, enables machine operation, a cartridge replacement warning count, and a termination count at which the cartridge is disabled from further use. The EEPROM stores updated counts of the remaining number of images left on the cartridge after each print run.
U.S. Pat. No. 5,272,503 to LeSueur et al. discloses a printing machine having operating parameters associated therewith. The printing machine includes a controller for controlling the operating parameters and an operator replaceable sub-assembly adapted to serve as a processing station in the printing machine. The operator replaceable sub-assembly includes a memory device, that communicates with the controller when the replaceable sub-assembly is coupled with the printing machine, for storing a value which varies as a function of the usage of the replaceable subassembly. The controller adjusts a selected one of the operating parameters in accordance with the stored value for maintaining printing quality of the printing machine.
U.S. Patent Publication No. 2003/0215247 describes a method for operating a machine using at least a first replaceable sub-assembly and at least a second replaceable sub-assembly. The method described comprises providing the first replaceable sub-assembly with a memory, the memory having stored within it a software code upgrade of executable instructions relating to the utilization of the second replaceable sub-assembly. The first replaceable sub-assembly is subsequently placed into the machine, the memory is used and a stored software code upgrade of executable instructions is placed into the machine as new machine software code. Then, the machine is operated with the second replaceable sub-assembly in accordance with the new machine software code.
U.S. Pat. No. 6,195,006 discloses an inventory system wherein articles, such as books, have radio frequency identification document (RFID) tags attached to them. Each tag has a unique identification or serial number for identifying the individual article. An inventory database tracks all of the tagged articles and maintains circulation status information for each article. Articles may be checked out of a library using a patron self-checkout system. Checked-out articles are returned to the library via patron self-checking devices. The shelves are periodically scanned with a mobile RFID scanner for updating inventory status.
All of the references indicated above are herein incorporated by reference in their entirety for their teachings.
As seen from these references, replaceable subassembly designs can be very dynamic over the life of the product they support. Even subtle design changes need to be tracked by the equipment manufacturer. Accordingly, different part numbers, configuration numbers, physical markings, and the like, may be assigned and/or attached to the replaceable subassembly. Sometimes even the packaging of the subassembly has to change over time. All of these changes, coupled with the ever increasing size of retail stores and the existence of different brands offered by large retail stores, can make it very difficult for a customer to find the correct replacement CRU for their application.